Conventionally, a base-controller constituted as a semiconductor integrated circuit device is designed to decode an external signal input designating the status of a microprocessor output and to output a control signal at appropriate timings. This conventional base-controller has a circuit construction using bipolar transistors, and there currently is no base-controller circuit with lowered power dissipation.
A prior art semiconductor integrated circuit device aiming to lower the power dissipation is an 8-bit parallel microprocessor M5M80C88P produced by Mitsubishi Electric Co., Ltd. This device has a sleep mode where some internal clocks are halted by executing the HALT instruction. Additionally, in this device external signals are decoded to halt the internal clocks in a special state, whereby the power dissipation is reduced.